xe2x80x9cTEST TOOL AND METHOD FOR FACILITATING TESTING OF DUPLEXED COMPUTER FUNCTIONSxe2x80x9d, Jones et al., (IBM Docket No. POU920010038US1), Ser. No. 09/968,420 filed herewith;
xe2x80x9cSYNCHRONIZING PROCESSING OF COMMANDS INVOKED AGAINST DUPLEXED COUPLING FACILITY STRUCTURESxe2x80x9d, Elko et al., (IBM Docket No. POU920010040US1), Ser. No. 09/968,179, filed herewith;
xe2x80x9cDYNAMICALLY DETERMINING WHETHER TO PROCESS REQUESTS SYNCHRONOUSLY OR ASYNCHRONOUSLYxe2x80x9d, Jordan et al., (IBM Docket No. POU920010043US1), Ser. No. 09/968,185, filed herewith;
xe2x80x9cMANAGING THE STATE OF COUPLING FACILITY STRUCTURESxe2x80x9d, Elko et al., (IBM Docket No. POU920010041US1), Ser. No. 09/968,248, filed herewith;
xe2x80x9cCOUPLING OF A PLURALITY OF COUPLING FACILITIES USING PEER LINKSxe2x80x9d,Brooks et al., (IBM Docket No. POU920010039US1), Ser. No. 09/968,244, filed herewith;
xe2x80x9cSYSTEM-MANAGED DUPLEXING OF COUPLING FACILITY STRUCTURESxe2x80x9d, Allen et al., (IBM Docket No. POU920010042US1), Ser. No. 09/968,242, filed herewith;
xe2x80x9cMETHOD, SYSTEM AND PROGRAM PRODUCTS FOR PROVIDING USER-MANAGED DUPLEXING OF COUPLING FACILITY CACHE STRUCTURESxe2x80x9d, Elko et al., (IBM Docket No. PO9-98-036), Ser. No. 09/255,382, filed Feb. 22, 1999;
xe2x80x9cCASTOUT PROCESSING FOR DUPLEXED CACHE STRUCTURESxe2x80x9d, Elko et al., (IBM Docket No. PO9-99-032), Ser. No. 09/255,383, filed Feb. 22, 1999;
xe2x80x9cSYSTEM-MANAGED REBUILD OF COUPLING FACILITY STRUCTURESxe2x80x9d, Allen et al., (IBM Docket No. PO9-99-096), Ser. No. 09/378,780, filed Aug. 23, 1999;
xe2x80x9cMETHOD, SYSTEM AND PROGRAM PRODUCTS FOR COPYING COUPLING FACILITY STRUCTURESxe2x80x9d, Allen et al., (IBM Docket No. PO9-99-138), Ser. No. 09/379,054, filed Aug. 23, 1999;
xe2x80x9cMETHOD, SYSTEM AND PROGRAM PRODUCTS FOR MODIFYING COUPLING FACILITY STRUCTURESxe2x80x9d, Dahlen et al., (IBM Docket No. PO9-99-137), Ser. No. 09/379,435, filed Aug. 23, 1999;
xe2x80x9cDIRECTED ALLOCATION OF COUPLING FACILITY STRUCTURESxe2x80x9d, Dahlen et al., (IBM Docket No. PO9-99-097), Ser. No. 09/378,861, filed Aug. 23, 1999;
xe2x80x9cMETHOD, SYSTEM AND PROGRAM PRODUCTS FOR COPYING COUPLING FACILITY LOCK STRUCTURESxe2x80x9d, Allen et al., (IBM Docket No. PO9-99-139), Ser. No. 09/379,053, filed Aug. 23, 1999;
xe2x80x9cMETHOD OF CONTROLLING THE FLOW OF INFORMATION BETWEEN SENDERS AND RECEIVERS ACROSS LINKS BEING USED AS CHANNELSxe2x80x9d, Gregg et al., (IBM Docket No. PO9-98-109), Serial No. 09/151,051, filed Sep. 10, 1998;
xe2x80x9cMETHOD OF CONTROLLING THE FLOW OF INFORMATION BETWEEN SENDERS AND RECEIVERS ACROSS LINKS BEING USED AS CHANNELSxe2x80x9d, Gregg et al., (IBM Docket No. PO9-98-124), Serial No. 09/150,942, filed Sep. 10, 1998;
xe2x80x9cMETHOD OF PERFORMING PARALLEL CLEANUP OF SEGMENTS OF A LOCK STRUCTURE LOCATED WITHIN A COUPLING FACILITYxe2x80x9d, Dahlen et al., U.S. Pat. No. 6,233,644 B1, issued May 15, 2001;
xe2x80x9cMULTI CHANNEL INTER-PROCESSOR COUPLING FACILITY PROCESSING RECEIVED COMMANDS STORED IN MEMORY ABSENT STATUS ERROR OF CHANNELSxe2x80x9d, Elko et al., U.S. Pat. No. 5,574,945, issued Nov. 12, 1996;
xe2x80x9cMETHOD, SYSTEM AND PROGRAM PRODUCTS FOR MANAGING CHANGED DATA OF CASTOUT CLASSESxe2x80x9d, Elko et al., U.S. Pat. No. 6,230,243 B1issued May 13, 1997;
xe2x80x9cDYNAMICALLY ASSIGNING A DUMP SPACE IN A SHARED DATA FACILITY TO RECEIVE DUMPING INFORMATION TO BE CAPTUREDxe2x80x9d, Elko et al., U.S. Pat. No. 5,664,155, issued Sep. 2, 1997;
xe2x80x9cMETHOD AND APPARATUS FOR DISTRIBUTED LOCKING OF SHARED DATA, EMPLOYING A CENTRAL COUPLING FACILITYxe2x80x9d, Elko et al., U.S. Pat. No. 5,339,427, issued Aug. 16, 1994;
xe2x80x9cMETHOD AND SYSTEM FOR LOG MANAGEMENT IN A COUPLED DATA PROCESSING SYSTEMxe2x80x9d, Geiner et al., U.S. Pat. No. 5,737,600, issued Apr. 7, 1998;
xe2x80x9cMETHOD OF PERFORMING PARALLEL CLEANUP OF SEGMENTS OF A LOCK STRUCTURExe2x80x9d, Dahlen et al., U.S. Pat. No. 6,178,421 B1, issued Jan. 23, 2001;
xe2x80x9cSPEEDING-UP COMMUNICATION RATES ON LINKS TRANSFERRING DATA STRUCTURES BY A METHOD OF HANDING SCATTER/GATHER OF STORAGE BLOCKS IN COMMANDED COMPUTER SYSTEMSxe2x80x9d, Gregg et al., U.S. Pat. No. 5,948,060, issued Sep. 7, 1999;
xe2x80x9cMETHOD OF MANAGING RESOURCES IN ONE OR MORE COUPLING FACILITIES COUPLED TO ONE OR MORE OPERATING SYSTEMS IN ONE OR MORE CENTRAL PROGRAMMING COMPLEXES USING S POLICYxe2x80x9d, Allen et al., U.S. Pat. No. 5,634,072, issued May 27, 1997;
xe2x80x9cMETHOD AND APPARATUS FOR OPTIMIZING THE HANDLING OF SYNCHRONOUS REQUESTS TO A COUPLING FACILITY IN A SYSPLE CONFIGURATIONxe2x80x9d, Kubala et al., U.S. Pat. No. 5,923,890, issued Jul. 13, 1999;
xe2x80x9cMETHOD FOR RECEIVING MESSAGES AT A COUPLING FACILITYxe2x80x9d, Elko et al., U.S. Pat. No. 5,706,432, issued Jan. 6, 1998;
xe2x80x9cCOMMAND EXECUTION SYSTEM FOR USING FIRST AND SECOND COMMANDS TO RESERVE AND STORE SECOND COMMAN RELATED STATUS INFORMATION IN MEMORY PORTION RESPECTIVELYxe2x80x9d, Elko et al., U.S. Pat. No. 5,392,397, issued Feb. 21, 1995;
xe2x80x9cSOFTWARE CACHE MANAGEMENT OF A SHARED ELECTRONIC STORE IN A SUPPLEXxe2x80x9d, Elko et al., U.S. Pat. No. 5,457,793, issued Oct. 10, 1995;
xe2x80x9cREQUESTING A DUMP OF INFORMATION STORED WITHIN A COUPLING FACILITY, IN WHICH THE DUMP INCLUDES SERVICEABILITY INFORMATION FROM AN OPERATING SYSTEM THAT LOST COMMUNICATION WITH THE COUPLING FACILITYxe2x80x9d, Neuhard et al., U.S. Pat. No. 5,860,115, issued Jan. 12, 1999;
xe2x80x9cAUTHORIZATION METHOD FOR CONDITIONAL COMMAND EXECUTIONxe2x80x9d, Elko et al., U.S. Pat. No. 5,450,590, issued Sep. 12, 1995;
xe2x80x9cIN A MULTIPROCESSING SYSTEM HAVING A COUPLING FACILITY, COMMUNICATING MESSAGES BETWEEN THE PROCESSORS AND THE COUPLING FACILITY IN EITHER A SYNCHRONOUS OPERATION OR AN ASYNCHRONOUS OPERATIONxe2x80x9d, Elko et al., U.S. Pat. No. 5,561,809, issued Oct. 1, 1996;
xe2x80x9cCOUPLING FACILITY FOR RECEIVING COMMANDS FROM PLURALITY OF HOSTS FOR ACTIVATING SELECTED CONNECTION PATHS TO I/O DEVICES AND MAINTAINING STATUS THEREOFxe2x80x9d, Elko et al., U.S. Pat. No. 5,463,736, issued Oct. 31, 1995;
xe2x80x9cMETHOD AND SYSTEM FOR MANAGING DATA AND USERS OF DATA IN A DATA PROCESSING SYSTEMxe2x80x9d, Allen et al., U.S. Pat. No. 5,465,359, issued Nov. 7, 1995;
xe2x80x9cMETHODS AND SYSTEMS FOR CREATING A STORAGE DUMP WITHIN A COUPLING FACILITY OF A MULTISYSTEM ENVIRONMENTxe2x80x9d, Elko et al., U.S. Pat. No. 5,761,739, issued Jun. 2, 1998;
xe2x80x9cMETHOD AND APPARATUS FOR COUPLING DATA PROCESSING SYSTEMSxe2x80x9d, Elko et al., U.S. Pat. No. 5,317,739, issued May 31, 1994;
xe2x80x9cMETHOD AND APPARATUS FOR EXPANSION, CONTRACTION, AND REAPPOTIONMENT OF STRUCTURED EXTERNAL STORAGE STRUCTURESxe2x80x9d, Dahlen et al., U.S. Pat. No. 5,581,737, issued Dec. 3, 1996;
xe2x80x9cSYSPLEX SHARED DATA COHERENCY METHODxe2x80x9d, Elko et al., U.S. Pat. No. 5,537,574, issued Jul. 16, 1996;
xe2x80x9cMULTIPLE PROCESSOR SYSTEM HAVING SOFTWARE FOR SELECTING SHARED CACHE ENTRIES ON A ASSOCIATED CASTOUT CLASS FOR TRANSFER TO A DASD WITH ONE I/O OPERATIONxe2x80x9d, Elko et al., U.S. Pat. No. 5,493,668, issued Feb. 20, 1996;
xe2x80x9cINTEGRITY OF DATA OBJECTS USED TO MAINTAIN STATE INFORMATION FOR SHARED DATA ATA LOCAL COMPLEXxe2x80x9d, Elko et al., U.S. Pat. No. 5,331,673, issued Jul. 19, 1994;
xe2x80x9cCOMMAND QUIESCE FUNCTIONxe2x80x9d, Elko et al., U.S. Pat. No. 5,339,405, issued Aug. 16, 1994;
xe2x80x9cMETHOD AND APPARATUS FOR PERFORMING CONDITIONAL OPERATIONS ON EXTERNALLY SHARED DATAxe2x80x9d, Elko et al., U.S. Pat. No. 5,742,830, issued Apr. 21, 1996;
xe2x80x9cMETHOD AND SYSTEM FOR RECONFIGURING A STORAGE STRUCTURE WITHIN A STRUCTURE PROCESSING FACILITYxe2x80x9d, Allen et al., U.S. Pat. No. 5,515,499, issued May 7, 1996;
xe2x80x9cMETHOD FOR COORDINATING EXECUTING PROGRAMS IN A DATA PROCESSING SYSTEMxe2x80x9d, Allen et al., U.S. Pat. No. 5,604,863, issued Feb. 18, 1997; and
xe2x80x9cSYSTEM AND METHOD FOR MANAGEMENT OF OBJECT TRANSITIONS IN AN EXTERNAL STORAGE FACILITY ACCESSED BY ONE OR MORE PROCESSORSxe2x80x9d, Dahlen et al., U.S. Pat. No. 5,887,135, issued Mar. 23, 1999;
This invention relates, in general, to data processing within a distributed computing environment, and in particular, to the duplexing of structures, such as structures of one or more coupling facilities.
Some distributed computing environments, such as Parallel Sysplexes, today provide a non-volatile shared storage device called the coupling facility, that includes multiple storage structures of either the cache or list type. These structures provide unique functions for the operating system and middleware products employed for the efficient operation of a Parallel Sysplex. For example, the cache structures provide directory structures and cross-invalidation mechanisms to maintain buffer coherency for multisystem databases, as well as a fast write medium for database updates. These are used by, for instance, the data sharing versions of DB2 and IMS, offered by International Business Machines Corporation, Armonk, N.Y.
The list structures provide many diverse functions. One such list structure function is to provide for high-performance global locking, and this function is exploited by such products as the IMS Resource Lock Manager (IRLM) and the Global Resource Serialization (GRS) function in OS/390, offered by International Business Machines Corporation, Armonk, N.Y. Another list structure function is to provide a message passing mechanism with storage for maintaining multiple messages on a per system basis and a mechanism for notifying a system of the arrival of new messages. This function is exploited by the XCF component of OS/390, which in turn is exploited by numerous multisystem applications for providing a capability to pass messages between their various instances. A third list structure function is to provide for shared queue structures that can be ordered and accessed by LIFO/FIFO ordering, by key, or by name. Workload Manager (WLM), IMS Shared Message Queues and MQ Series, all offered by International Business Machines Corporation, Armonk, N.Y., are examples of exploiters of this feature. While these functions provide examples of the list structure uses, other uses exist.
Various components of a Parallel Sysplex have been documented in numerous applications/patents, which are listed above and hereby incorporated herein by reference in their entirety. The capabilities defined in some of those patents provide the basic system structure to create and manage cache and list structure instances. Additionally, various of the applications/patents listed above provide extensions to the base functions of the Parallel Sysplex.
In many situations, a failure of the coupling facility that contains various structures requires significant recovery actions to be taken by the owning applications. For example, for database caches and queues, this may require using backup log data sets and/or tapes. This is a time-consuming process that results in a loss of access to the application during the recovery operation. Other structures, such as lock tables, may require reconstruction of partial lock tables from in-storage copies, along with failures of in-flight transactions. Still other structures, such as message-passing structures, may lose all data and require re-entry from the application. So, there is a proliferation of diverse recovery schemes with different recovery times and impacts. Moreover, since the failure of a coupling facility results in all resident structures failing, the diverse recovery actions are occurring concurrently, which can cause serious disruptions in the Parallel Sysplex.
Thus, a need exists for a configuration of a Parallel Sysplex that provides less disruptions. In particular, a need exists for a high-availability coupling facility, which improves on the recovery times and impacts of existing recovery techniques, while also provides for a consistent recovery design across various structure types. As a particular example, a need exists for one or more capabilities that facilitate duplexing of structures in separate coupling facilities coupled to one another.
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a method of restarting coupling facility commands. The method includes, for instance, obtaining from one coupling facility command a token to be used in restarting another coupling facility command, the another coupling facility command being different from the one coupling facility command; and using the token to restart the another coupling facility command. In one embodiment, the another coupling facility command is a duplexed command.
System and computer program products corresponding to the above-summarized methods are also described and claimed herein.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention.